Intelsat II

Intelsat II was a series of four communications satellites operated by Intelsat which were launched in 1966 and 1967. Built by the Hughes Aircraft Company, the Intelsat II series was a follow-up to the Intelsat I series, of which only one satellite was launched.

Intelsat II spacecraft were based on the HS-303A satellite bus, which was cylindrical in shape and spin-stabilised. The satellites had a diameter of 1.42 metres (4 ft 8 in), and were 0.67 metres (2 ft 2 in) long.^[2] They were equipped with an SVM-1 apogee motor to circularise their orbits following launch atop Delta E1 carrier rockets. All four satellites were launched from Launch Complex 17B at the Cape Kennedy Air Station. Each satellite had a mass at launch of 162 kilograms (357 lb), which decreased to around 86 kilograms (190 lb) once the satellite had fired its apogee motor and manoeuvred into its orbital position.^[3]

Intelsat II spacecraft were designed to be operated in geostationary orbit; however the first satellite's apogee motor malfunctioned leaving it in a lower than planned orbit.^[4] It was able to perform a limited communications mission, however the other three spacecraft successfully achieved geostationary orbit. Each satellite carried two transponders, powered by solar cells mounted on the body of the spacecraft, which generated 85 watts of power.